This invention relates to an improved valve to be used for a pressurized container and more particularly to one that is adapted to be used in a pressurized dispensing container for a product which is highly viscous and/or contains fibers or which for any reason tends to clog in the valve through which it is dispensed.
Hand held pressurized dispensing containers having a tilt action valve assembly have been known for a long time. Applicant""s U.S. Pat. No. 5,785,301 is representative of a prior art valve design for use in these pressurized dispensing containers. The sidewall at the base of the stem of the tilt valve has four openings so that when the valve is tilted, at least one opening will be exposed to the contents of the can so that the contents, under pressure from a pressurized piston container, will be dispensed through the opening in the valve stem.
It has been found that when discharging fibrous materials, the fibers tend to wrap around the wall segments or legs separating the openings thereby reducing the size of the opening and blocking flow of material.
These tilt valves, and other related type of valves, for pressurized dispensing containers have been in existence for many decades. Yet the problem of obtaining smooth and continuous flow from fiber containing materials has not been adequately resolved.
Accordingly, it is major purpose of this invention to provide a valve design for pressurized dispensing containers from which fibrous materials can be dispensed.
It is a related purpose of this invention to provide such a valve design in a fashion that will provide reliable, repeatable flow so that the flow will be similar from can to can and will be substantially consistent during dispensing from any particular can.
In brief, the pressurized dispensing can valve of this invention provides a single valve stem sidewall opening that is in full communication with the material to be dispensed. Such an arrangement assures that no leg between two sidewall openings is presented to the material involved. Thus the design assures there is no substrate on which fibrous material can build up to clog the openings.
For example, instead of the four openings known in the art each of which has a span of between 50xc2x0 and 60xc2x0, the openings in the valve described herein are closer to 110xc2x0 in circumference and there is at the most two such openings.
In order to assure that the full span of an opening is presented to the material being dispensed when the valve is tilted, a nozzle with a dispensing handle is provided. The nozzle is caused to be fully seated at a predetermined circumferential position, at which position the nozzle handle is aligned with the opening so that when the nozzle handle is actuated, the full span of a single sidewall opening is presented to and is in communication with the product to be dispensed. Thus, no leg exists to catch the fibers.
A combination of the large stem sidewall opening and the great pressure required for the product will cause the rubber like seal to flow or creep into the valve stem sidewall opening thereby reducing the effectiveness of the opening to achieve the objects of this invention. A feature which has been found to minimize this effect is to provide a small retaining wall between the lower edge of the valve stem sidewall opening and the valve seat which abuts against the lower end of the sealing grommet or rubber.